When did Windows start accepting forward slash as a path separator?

Grant Edwards grante at visi.com
Fri Sep 26 04:54:19 CEST 2003

In article <b16e4ef7.0309251550.724a57f at posting.google.com>, Stephen Ferg wrote:

> When did Windows start accepting the forward slash as a path separator
> character?

Sometime prior to 1983.  DOS has always accepted it, and I assume Windows
always has as well.

> At one time, it was accepted as a truism that Windows (like MS-DOS)
> was different from Unix because Windows used the backslash as the path
> separator character,

Accepted as a truism by whom?  DOS would accept either.  The shell's "switch"
character was configurable as well -- it defaulted to '/' but changing it to
'-' was trivial.

> whereas Unix used the forward slash.

> But now, among a small group of cognoscenti, it is a truism that this
> is a myth, and that Windows will allow you to use either the forward
> or the backward slash as a pathname separator.

I don't remember if the actual DOS system calls accepted '/' or if the C
library translated.  I do know that DOS C programs could use '/' for path
separator at least 20 years ago.

> I hypothesize that originally Windows accepted only the backslash, and then
> at some time it changed to accept the forward slash as well.

Nope.  AFAIK, it's always accepted '/'.  I did C programming on DOS for
years, and I always used '/' since it was too error working with string
literals in C that contain '\'.  Those same programs seemed to run fine
under Windows.

> Does anyone know when that change occurred?  Was it with the introduction of
> support for long filenames in NT and Win95?

I'm not aware that there has ever been a "change".  '/' has been OK since
the early DOS days.

Grant Edwards                   grante             Yow!  WHOA!! Ken and
                                  at               Barbie are having TOO
                               visi.com            MUCH FUN!! It must be the
                                                   NEGATIVE IONS!!

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